Difference between revisions of "A choose b"

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== Why is it important? ==
 
== Why is it important? ==
a choose b counts the number of ways you can pick b things from a set of a things. For example $\binom{8}{2}=\frac{8!}{2!(8-2)!}=\frac{8(7)}{2}=\frac{42}{2}=21
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a choose b counts the number of ways you can pick b things from a set of a things. For example <math>\binom{8}{2}=\frac{8!}{2!(8-2)!}=\frac{8(7)}{2}=\frac{42}{2}=21</math>

Revision as of 16:52, 15 June 2019

Here is the formula for a choose b: $\binom{a}{b}=\frac{a!}{b!(a-b)!}$. This is assuming that of course $a \ge b$.

Why is it important?

a choose b counts the number of ways you can pick b things from a set of a things. For example $\binom{8}{2}=\frac{8!}{2!(8-2)!}=\frac{8(7)}{2}=\frac{42}{2}=21$